Cellulose-ether solvent and composition



Patented Apr. 3, 1923.

UNITED STATES PATENT OFFICE.

STEWART 'J'. CARROLL, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

CELLULOSE-ETHER SOLVENT AND C OMPOSITION No Drawing.

To all whom it may concern:

Be it known that I, STEWART J. CARROLL,

a citizen of the United States of America,

residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Cellulose-Ether Solvents and Compositions, of which the following is a full, clear, and exact specification.

This invention relates to solvents for making strong solutions of cellulose ether 1 and also relates to the cellulose ether compositions produced by the aid of such solvents. One object of my invention is to provide a solvent which will dissolve such large proportions of cellulose ethers that thick or viscous fiowable solutions may be obtained for use in plastic and film making arts. Another object of my invention is to provide a cellulose ether solution which may be manufactured into strong, flexible, transparent film o 'n)the machines and by the methods now in use.

In U. S. Patent No. 1,188,376, Lilienfeld,

June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in water, and my invention relates, but is not limited, to the ethers having that property. While the ethers form thin solutions in the lower monohydroxy aliphatic alcohols'or methyl salicylate, it has been found that such single solvents by themselves do not dissolve a sufficient pro ortion of the ethers to make a desirably t ick flowable composition or dope such as may be used in the manufacture o photographic film base by customary methods, or in the other plastic arts.

I have discovered that an adequately strong and useful solvent may be prepared by mlxing' methyl salicylate with one or more of the lower monohydroxyaliphatic alcohols. For example, I may use from 90 to 50 parts of methyl salic late and 10 to 50 parts by weight of the alco ol, say methyl or ethyl alcohol as an illustration. In the preferred form of my invention, I use equal parts by weight of meth l salicylate and methyl or ethyl alcohol. lle the amount ofether that may be dissolved insuch mixed solvents maybe varied as desired over a large range, it is noted, forthe'sake of exam.-

Application filed May 24, 1921. Serial No. 472,271.

ple, that 1 art by weight of water in soluble ethyl cellulose when dissolved in 5 parts of one of the above mixed or compound solvents yields a thick viscous flowable solution.

Other substances which impart additional suppleness, or incombustibility, or other qualities, to the film may also. be added to the dope, such, for instance, as triphenyl or tricresyl phosphate, camphor,-etc. In the formation of the film a considerable amount of methyl salicylate is left therein, due to its relatively low volatility. It imparts useful properties to such film.

The ingredients are of the ordinary commercial type and sufiiciently purified for the process of film manufacture, so as to give a dope yielding film having the proper relative freedom from color. The viscous-flowable dope above described can be used in connection with the usual fihn-forming apparatus without the necessity of expensive alterations in the latter. By lowerv monohydroxy aliphatic alcohol I include one havin less than six carbon atoms.

aving thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A composition of matter, comprising cellulose ether dissolved in a mixture containing methyl salicylate and a lower monohydroxy alip atic alcohol. I

2. A viscous flowable composition,-comprising an alkyl ether of cellulose dissolved in a solvent containing from 90 to 50 parts by weight of methyl salicylate and 10 to 50 parts of a lower monohydroxy aliphatic alcohol.

3. A composition of matter, comprising water-insoluble ethyl cellulose, methyl salicylate and methyl alcohol.

4. A composition of matter comprising cellulose ether and methyl salicylate.

5. A composition of matter comprising water-insoluble ethyl cellulose and methyl salicylate. 4

6. As an article of. manufacture, a deposited or flowed flexible film comprising cellulose ether and methyl salicylate.

Signed at Rochester, New York, this 14th day of May, 1921.

STEWART 1T. CARROLL. 

